Hmm.. that's how I felt when I was drinking, to be honest (or the next day!). Anna has a great point.. What else have you changed?
I had to change a lot of my habits, entertainment choices, friends, foods, restructure my time, find NEW things to do, I had to replace my time, and my ways to achieve the 'mood shift' that alcohol gave me, since I wasn't going to use it anymore.
Hard stuff, especially realizing that quitting drinking really was only the very small beginning of living a sober life.